chore: regens API reference docs (#889)

diff --git a/docs/dyn/books_v1.mylibrary.annotations.html b/docs/dyn/books_v1.mylibrary.annotations.html
index 44850a8..25a1f1b 100644
--- a/docs/dyn/books_v1.mylibrary.annotations.html
+++ b/docs/dyn/books_v1.mylibrary.annotations.html
@@ -78,7 +78,7 @@
   <code><a href="#delete">delete(annotationId, source=None)</a></code></p>
 <p class="firstline">Deletes an annotation.</p>
 <p class="toc_element">
-  <code><a href="#insert">insert(body, source=None, country=None, showOnlySummaryInResponse=None, annotationId=None)</a></code></p>
+  <code><a href="#insert">insert(body=None, source=None, country=None, showOnlySummaryInResponse=None, annotationId=None)</a></code></p>
 <p class="firstline">Inserts a new annotation.</p>
 <p class="toc_element">
   <code><a href="#list">list(layerId=None, pageToken=None, layerIds=None, volumeId=None, maxResults=None, showDeleted=None, updatedMax=None, contentVersion=None, source=None, updatedMin=None)</a></code></p>
@@ -90,7 +90,7 @@
   <code><a href="#summary">summary(layerIds, volumeId)</a></code></p>
 <p class="firstline">Gets the summary of specified layers.</p>
 <p class="toc_element">
-  <code><a href="#update">update(annotationId, body, source=None)</a></code></p>
+  <code><a href="#update">update(annotationId, body=None, source=None)</a></code></p>
 <p class="firstline">Updates an existing annotation.</p>
 <h3>Method Details</h3>
 <div class="method">
@@ -104,11 +104,11 @@
 </div>
 
 <div class="method">
-    <code class="details" id="insert">insert(body, source=None, country=None, showOnlySummaryInResponse=None, annotationId=None)</code>
+    <code class="details" id="insert">insert(body=None, source=None, country=None, showOnlySummaryInResponse=None, annotationId=None)</code>
   <pre>Inserts a new annotation.
 
 Args:
-  body: object, The request body. (required)
+  body: object, The request body.
     The object takes the form of:
 
 {
@@ -421,12 +421,12 @@
 </div>
 
 <div class="method">
-    <code class="details" id="update">update(annotationId, body, source=None)</code>
+    <code class="details" id="update">update(annotationId, body=None, source=None)</code>
   <pre>Updates an existing annotation.
 
 Args:
   annotationId: string, The ID for the annotation to update. (required)
-  body: object, The request body. (required)
+  body: object, The request body.
     The object takes the form of:
 
 {